Elevator systems



Sept. 17, 1957 J. suozzo ELEVATOR SYSTEMS 7 Sheets-Sheet 2 Filed May 23, 1956 4 3 B H B P 1957 J. suozzo 2,806,555

ELEVATOR SYSTEMS Filed May 23, 1956 '1 sheets-51 m 4 69A L 69A Fig.3.

4 Sept. 17, 1957 J. SUOZZO ELEVATOR SYSTEMS Filed May 23, 1956 7 Sheets-Sheet 6 IDIOT3 DN4 United States Patent ELEVATOR SYSTEMS John Suozzo, Paramus, N. J., assignor to Westinghouse Electric CorporatiomEast Pittsburgh, Pa., a corporation of Pennsylvania Application May 23, 1956, Serial No. 586,753

9 Claims. (Cl. 187-29) This invention relates to elevator systems and it has particular relation to elevator systems which are designed for operation without car attendants.

Although aspects of the invention may be employed in elevator systems having car attendants, the invention is particularly desirable for elevator systems of the automatic type which do not have car attendants. For this reason, the invention will be discussed with particular reference to such operatorless systems.

When an elevator car in an operatorless system stops at a landing, such as a floor of a building or structure, it is the practice to hold the elevator car at the floor for a substantial time in order to permit loading and unloading of the elevator car. This time is referred to as a noninterference time. In the prior art systems, the noninterference time may be of the order of 5 or more seconds for each stop.

The non-interference time may be varied in accordance with the requirements for each of the floors at which a stopis made. To this end, the elevator system is designed to hold an elevator car at a floor at which the elevator stops for a non-interference substantial time, such as 5 seconds. 7

The non-interference time for a car call may differ from that employed for a floor call. Thus, if a passenger within the elevator car registers a call for a floor, the elevator car may be held at such floor for a non-interference time of the order of say three seconds. However, if the elevator car stops in response to a floor call registered by an intending passenger at one of the intermediate floors, a longer non-interference time, to allow a passenger to walk to the car that is stopping from the farthest point of the corridor, such as 5 to 7 seconds may be employed.

In one system to which the invention may be applied a substantial non-interference time is provided for each stop'of the elevator car. However, upon movement of a passengerinto or out of the elevator car, the non-interference time is reset to a smaller value which may be larger for a stop made in response to a floor call than for a stop made in response to a car call. For example, if the elevator car stops at a floor in response to a car call, the elevator car door opensand remains open for a noninterference time of the order of five seconds if no one leaves or enters the elevator car. However, as soon as a person leaves or enters the elevator car, the non-interference time is reset to a value'of the order of one-half second. The non-interference time similarly is reset for a time of the order of one-half second each time a successive passenger leaves or enters the elevator car. If no passenger enters or leaves the elevator car after the predetermined time has elapsed for a period in excess of one-half second, the door starts to close. Once the door starts to close, it may continue to its completely closed position despite the attempt of additional passengers to enter the elevator car or leave the elevator car provided the elevator car is in condition to run. Alternatively, the elevator car door may be conditioned to open each time a passenger attempts to enter or leave the elevator car as the elevator car reaches a predetermined load transfer Patented Sept. 17, 1957 before the elevator car door completely closes. When this happens, the door does not start to close until a short time such as one-half second after the last passenger has passed through the doorway. A system of this type is disclosed in the Keiper copending application, Serial No. 406,706, filed January 28, 1954, in the Santini patent application, Serial No. 427,476, filed May 4, 1954, and in the Santini et a1. patent application, Serial No. 427,475, filed May 4, 1954, all of which are assigned to the same assignee.

If the elevator car stops in response to a registered floor call at an intermediate floor, the elevator car door again is opened and remains open for a substantial non-interference time, such as five seconds. However, if a person enters or leaves the elevator car, the non-interference time is reset for a smaller value, such as two seconds. If succeeding persons enter or leave the elevator car at close enough intervals, the non-interference time is reset for each of the persons for a time which may be of the order of one-half second in order to delay the reclosure of the door.

If the elevator car stops at an intermediate floor in response to a registered floor call and is assigned to reverse at such floor, the door may open for a non-interfen ence time of the order of five seconds. In this case, entry of a person into the car or departure of a passenger from the car may reset the non-interference time to a smaller value of the order of one-half second. Each succeeding person entering or leaving the elevator car within suit able intervals may reset the non-interference time for an interval of the order of one-half second to delay reclosure of the door.

The movement of a passenger or an intending passenger, into or out of the elevator car can be determined by trans-, mitting energy into the passage traversed by such passenger. Interruption of such energy path by a passenger is ascertained by a suitable detector.

In some cases, a passenger may attempt to prevent the closure of the door for an unreasonably long time by standing in the path of the transmitted energy. If

the energy is interrupted for an unduly long period, such" as four seconds, a closing movement of the door is initiated promptly at the close of such period. Desirably the door may be provided with a protective edge which,

initiates the stopping or reopening of the door if the door reaches a person located in the closing path of the door.

If as the door reopens the path for the energy is reestab-I lished the door will remain open for the required onehalf second and will not start to reclose as long as the path is interrupted at less than one-half second intervalsf After the movement into or out of the elevator car starts, successive loads'or'passengers ordinarily follow the first load or passenger rapidly. Each load or pas:-

senger after the first one resets the non-interference time for an additional small time of the order of one-half second. Consequently, waste time is substantially eliminated and the efiiciency of the elevator system is materially improved.

At terminal floors, it may be desirable to control the In a suitable system, an elevator car is provided with a passage through which load, such as a passenger, may enter and leave the elevator car. The passage may be exposed or closed by a door which is automatically opened position which ordinarily is a landing or floor of a buildmg. Upon expiration of the non-interference time, the door may be closed for the purpose of permitting departure of the elevator car. I

A signal or energy is established or transmitted across the passage. A detector is provided which is responsive to a function of the signal or energy. For example, the detector may be responsive to the presence or absence of radiant energy. If a load, such as a passenger, enters the area through which the radiant energy is projected, the detector senses the presence of such load. The detector, in turn, controls mechanism which, in response to the movement of the load through the passage, resets the non-interference time in the manner previously described. If the detector receives no radiant energy for more than a predetermined time the door may be promptly closed.

Ifthe closure of the door is prevented for more than. a reasonable time, a closing force may be exerted on the door continuously until the door closes. The system may be so arranged that the closing force is exerted'unless safety edges on both sides of the door openings are operated.

If; an elevator car is substantially loaded at'the time it answers a registered car call, interference among passengers within the elevator car may delay prompt departure of a passenger desiring to leave the elevator car. For example, if a first passenger located adjacent the door of the elevator car and a second passenger located toward the rear of a fully loaded elevator car desire to leave the car at a floor, the second passenger may have difiiculty in working his way through the other passengers in the elevator car.

- In accordance with the invention, the delay in departure of the elevator car following each movement of a passenger from the elevator car is made dependent on the loading of the elevator car. Thus, if the elevator car is lightly loaded, the delay may be of the order of onehalf second. However, if the elevator car is substantially loaded, the delay in departure following movement of each passenger from the elevator car may be of the order of one and one-half seconds. This assures ample time for unloading of passengers of a full elevator car.

Aspreviously pointed out, the delay in departure of the elevator car following each movement of a passenger through the elevator car doorway may be of the order of one-half second. In accordance with a further aspect of the invention, this delay is different for a floor call and fora car call. For example, if the elevator car answers a floor call, the delay in departure of the elevator car for each movement of a passenger into the elevator car may be of the order of nine-tenths of a second. If the elevator car answers a car call, the delay in departure of the elevator car following each movement of a passenger from the elevator car may be of the order of one-half second. This difference in delay compensates for the greater spacing of prospective passengers who are awaiting arrival of the elevator carat a floor, as compared to the spacing of passengers in the elevator car.

It is, therefore, an object of the invention to provide an elevator system having improved door operation.

It is a further object of the invention to provide an improved elevator system wherein the delay in departure of an elevator car from a floor following movement of a passenger through the elevator car doorway varies in accordance with traffic conditions.

It is also an object of the invention to provide an elevator system wherein the delay in departure of an elevator car for each movement of a passenger from the elevator car varies as a function of the loading of the elevator car.

It is an additional object of the invention to provide an elevator system wherein the delay in departure of an elevator car from a floor following each movement of a passenger through the doorway of the elevator car as a first value for a stop made in response to a registered car call and a second value for a stop made in response to a registered floor call.

Other objects of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic view with parts in elevation and parts broken away of an elevator system which may embody the invention;

Fig. 1A is a View in section showing an elevator car employed in Fig. 1 associated with a hoistway;

Figs. 2, 3 and 4 are schematic views including circuits in straight-line form of a control system embodying the invention;

Fig. 5 is a schematic view including circuits in straightline form of a modified control system embodying the invention; and

Figs. 2A, 3A and 4A are key representations of electromagnetic relays and switches employed in the circuits of Figs. 2, 3 and 4. If Figs. 2, 3 and 4 are horizontally aligned respectively with Figs. 2A, 3A and 4A, it will be found that coils and contacts of the switches and relays appearing in the key representations are horizontally aligned with the corresponding coils and contacts shown in these circuits.

. Although the invention may be incorporated in an elevator system employing various numbers of elevator cars serving buildings or structures having various numbers of floors, the invention can be described adequately with reference to an elevator system having four elevator cars serving av building having five floors. The elevator cars may be dispatched from any desired floors. The elevator cars will be assumed to be dispatched between the first floor and the upper terminal or fifth floor.

Because of the complexity of such systems, certain conventions have been adopted. The elevator carswill be identified by the reference characters A, B, C and D. Since the circuits for the cars are similar, substantially complete circuits are shown for the cars A and B. Components associated with the cars C and D are discussed only as required.

Components associated with the elevator cars B, C and D which correspond to a component of the elevator car A are identified by the same reference character em-' ployed for the component of the elevator car A preceded by the letters B, C and D, respectively. For example, the reference characters U, BU, CU and DU designate up switches, respectively, for the elevator cars A, B, C and D. The discussion will be directed primarily to the apparatus and circuits for the elevator car A.

The various relays and switches employed in the circuits may have break or back contacts which are closed when the relay is deenergized and dropped out. The break contacts are open when the relays or switches are energized and picked up.

The relays and switches also may have front or make contacts which are opened when the switches and relays are deenergized and dropped out. These contacts are closed when the switches and relays are energized and picked up. In the drawings the various switches and relays are shown in so far as possible to their deenergized and dropped-out conditions.

Each set of the contacts associated with a relay or switch is identified by the reference character associated with the relay or switch followed by a numeral identifying the specific set of contacts. Thus, the reference characters U1, U2 and U3 designated, respectively, the first, second and third sets of contacts of the up switch U.

In order to facilitate the presentation of the invention, the apparatus shown in the figures will be briefly set forth, andthe operation of the, complete system thereafter will be discussed. The system includes in part the following apparatus:

accuse Apparatus specific to car A v speed relay Uup switch Mcar-running relay DdOWI1 switch G-holding relay Eslowdown inductor relay F-stopping inductor relay Wup-preference relay Xdown-preference relay 70Ttiming relay TT--car-call stopping relay K-fioor-call stopping relay 80-main starting relay L--car-position relay N-loading relay S -auxiliary starting relay 438floor-call detector relay 40door relay 45door-contro1 relay Dcadoor-close solenoid DO-door-open solenoid SR-detector relay LWA, NU, NUA, 70HT, SRT-time delay relays 300expediter relay J-reversal relay Apparatus common to all cars 2DR to 5DR--down floor-call storing relays 2UR to 4URup floor-call storing relays FIGURE 1 Fig. 1 illustrates the structural relationships of the elevator cars A, B and associated apparatus with reference to the building structure which the elevator cars are intended to serve.

The elevator car A and a counterweight are secured to opposite ends of a rope or cable 11 which passes over a sheave 13. The sheave 13 is mounted on the shaft 14 of an elevator driving motor 15. The shaft 14 also carries a brake drum 16 with which a brake 17 of the conventional spring-applied electrically-released type is associated. The motor is secured to the floor 18 of a penthouse located in the structure which the elevator car is intended to serve.

In order to simplify the association of control circuits with the elevator car A, a control device 19 is provided which is operated in accordance with a 'function of the V movement of the elevator car A. In the specific embodiment of Fig. 1, the control device takes the form of a floor selector which includes an insulating panel 20 and a brush carriage 21. A screw 22 is mounted for rotation relative to the panel 20. This screw conveniently may be coupled through suitable gearing to the shaft 14 for rotation in accordance with movement of the elevator car A.

The brush carriage 21 is in threaded engagement with the screw 22. As the elevator car A moves upwardly, the brush carriage 21 is moved upwardly but at a rate much slower than the rate of movement of the elevator car. Similarly, when the elevator car A moves down wardly, the brush carriage 21 also moves downwardly at a slower rate.

The panel 20 carries a plurality of contact segments which are insulated from each other. Thus, the contact segments 02 to :5 are arranged in a row on the panel 20. As the eievator car proceeds upwardly from the basement, a brush 23 mounted on the carriage 21 successively engages the contact segments a2 to a5, as the elevator car approaches respectively the floors 2 to 5 of the structure. It will be understood that the contact segments 02 to a5 are spaced from each other in accordance with the spacing of the floors. A will be pointed out below, these contact segments are employed with circuits controlling the stopping of the elevator car during in response to car calls.

As a further example, the panel 20 has a single contact segment e1 which is engaged by a brush 24 mounted on the carriage 21 only when the elevator car A is adjacent the first or dispatching floor. As will be pointed out below, this contact segment is employed in controlling the operation of a dispatching device.

It will be understood that a number of rows of contact segments and a number of brushes may be employed in the floor selector. However, the fore-going discussion is believed sufficient to illustrate the mechanical relationships of these contact segments and brushes.

Certain apparatus is mounted on or in the elevator car A. Thus, car-call buttons 2c to 5c are provided for registering car calls for the second, third and fourth floors, respectively.

A slowdown-inductor relay E is provided for the purpose of initiating a slowdown of the elevator car A as it approaches a floor at which it is to stop. The inductor relay may be of conventional construction and includes two sets of break contacts E1 and E2. When the coil of the inductor relay E is energized, the contacts remain in the positions illustrated in Fig. 1 until the relay is adjacent an inductor plate located in the hoistway of the elevator car A. For example, when the coil of the inductor relay E is energized and the inductor relay is adjacent the magnetic plate UEP for the second floor, the magnetic circuit is completed, which results in opening of the break contacts E1. When open, the contacts remain open until the coil of the inductor relay E is deenergized. The inductor plate UEP is positioned to be reached by the inductor relay E as the elevator car approaches the second floor for the purpose of initiating slowdown of the ele* vator car. It will be understood that a similar inductor pla.e is similarly associated with each of the floors at which the elevator car is required to stop during up travel.

If the coil of the inductor relay E is energized during down travel of the elevator car, and if the relay reaches the inductor plate DEP for the second floor, a magnetic circuit is completed which results in opening of the break contacts E2. When opened, the contacts remain open until the coil is deenergized. The inductor plate DEP is so positioned that it initiates slowdown of the elevator car A a suitable distance from the second floor. A similar inductor plate would be similarly associated with each of the floors at which the elevator car A is to stop during down travel.

The elevator car A also carries a stopping inductor relay P which is similar in construction to the inductor relay This relay is employed for initiating a stopping operation of the elevator car A. The stopping inductor relay F cooperates with inductor plates UFP and DFP in a manner which will be clear from the discussion of the cooperation of the slowdown inductor relay with the inductor plates UEP and DEP. If the coil of the relay F is energized and if the elevator car is to stop at the second floor while traveling up, when the inductor relay F reaches the inductor plate UFP a magnetic circuit is completed which results in opening of the break contacts F1. This initiates a stopping operation of the elevator car. An inductor plate similar to the plate UFP i similarly associated with each of the floors at which the ele vator car A is to stop during up travel thereof. If the elevator car A during down travel is to stop at the second floor, the coil of the stopping inductor relay F is energized, and when the inductor relay reaches the inductor plate DFP for the second floor, a magnetic circuit is completed which results in opening of the contacts F2. This initiates a stopping operation of the elevator car A. It will be understood that an inductor plate similar to the inductor plate DFP is similarly associated with each of the floors at which the elevator A is to stop during down travel thereof.

The elevator car A also carries a mechanical switch 63 which is positioned to be operated by cams 26 locatedup travel in the hoistway associated with the elevator car. The mechanical switch 63 normally is closed and is opened by a cam 26 when the elevator car A is adjacent the first or dispatching floor and by a similar cam when the car is at the upper terminal floor. It will be understood that other mechanical switches may be operated in a similar manner by the elevator car A.

An intending passenger on the fourth floor may register a floor call for elevator car service in the up direction by pressing a button of a push-button switch 4U. A similar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in an up direction.

If the intending passenger at the fourth floor desires to proceed in a down direction, he may press the button of a push-button switch 4D located at the fourth floor. A simiiar push-button switch is located at each of the intermediate floors from which an intending passenger may desire to proceed in a down direction.

The elevator car A is provided with a door DP which is mounted to slide across the passage through which passengers enter and leave the elevator car. The door is moved by means of a lever 28 which is pivotally mounted on the car by means of a pivot 28A. The lever 28 is moved in a clockwise direction about a pivot by means of a doorclose solenoid DC for the purpose of closing the passage and is moved in a counterclockwise movement about its passage to open the door by means of a door-open solenoid DO.

When the door is open an object-detecting device is effective. This device preferably includes, a signal or energy which is projected across the passage through which passengers enter and leave the elevator car. This signal may be of any type which can be modified by the movement of a passenger through the passage and in which the modification produced'by such movement may be detected. For example, the signal may be in the form of infrared radiant energy or ultra-violet radiant energy. As a further example, supersonic energy may be projected across the passage. However, it will be assumed that the energy is in the form of visible light which is produced by a lamp LA1 mounted on the edge of the door which is the leading edge during a closing movement of the door. The light is in the form of a beam which is focused in any suitable manner on a suitable detector such as a photocell PCl. The output of the photocell may be amplified by means of an amplifier AM1 which is supplied with electrical energy from a suitable source and the output of the amplifier is applied to a relay PR1. The relay PR1 may be designed to be picked up as long as the photocell PCl receives the beam of radiant energy. Detectors of this type are well known in the art. Examples of such detectors may be found in the Kinnard et al. Patent 1,822,152 and in the Ellis, Jr., Patent 1,947,079.

Although a single beam may suffice, in some cases it is generally desirable to employ a plurality of beams. Such beams may be produced by interposing suitable reflectors between the lamp LA1 and the photocell PCI to reflect a beam across the passage several times before it reaches the photocell. However, for present purposes, it will be assumed that separate lamps and photocells are employed for each of the beams. Thus, in Fig. 1A, a second lamp LA2 is provided for projecting energy toward a photocell PCZ which is associated with an amplifier AM2 and a relay PR2.

In the embodiment thus far described, the lamp LA1 is mounted on one edge of the door DP. If desired, a lamp and a photocell may be placed in any positions wherein the beam between the lamp and photocell is interrupted by the entry of load into the elevator car or the departure of load from the elevator car. Thus the beam may be located between the car and hoistway doors or it may be adjacent the hoistway door. A beam positioned about twelve inches above the floor has been found suitable.

In Fig. 1A, a hoistway door DPH is provided which is coupled to the door DP for movement therewith when the elevator car is stopped at a floor. It will be understood that a separate hoistway door DPH is provided for each of the fioors served by the elevator car. The coupling of the two doors may be effected in a conventional manner as by a vane DPV which is secured to the door DP for reception in the slot of a slotted block DPB which is mounted on the hoistway door DPH.

The hoistway door DPH is moved to close and expose a hoistway passage through which load enters and leaves the elevator car. As shown in Fig. 1A, the lamp LA2 is mounted on a hoistway wall or door jamb to project radiant energy across the hoistway passage towards the photocell PC2 which also is mounted on a hoistway wall. By inspection of Fig. 1A, it will be observed that the radiant energy transmitted from the lamp LAZ to the photocell PC2 is interrupted each time a passenger enters or leaves the elevator car.

If desired, the edge of the door DP which is the leading edge during a door-closing movement may have an object-sensing device such as a safety-edge SE of conventional type. When such an edge reaches an obstruction, it opens switches SE1, SE2 and SE3 which may be employed in circuits to stop or reopen the door or for other purposes. If center-opening doors are employed, a separate safety edge may be provided for the edge of each door which is a leading edge during closing movement. In the present case, it will be assumed that the second safety edge SEA is located on the elevator car adjacent the photocells PCl, PC2. The safety edge SEA operates switches SEAl and SEAZ for three purposes hereinafter set forth.

The load in the elevator car is weighed in any suitable manner as by the deflection of a spring-mounted platform PL. Loads in excess of say 80 percent of rated capacity open the normally-closed load weighing switch LW, and close normally-open load weighing switches LWl and LWZ.

FIGURE 2 Fig. 2 shows circuits for the driving motor, the brake, the speed relay V, the up switch U, the down switch D, the car-running relay M, the holding relay G, the slowdown inductor relay E, the stopping inductor relay F, the up-preference relay W, the down-preference relay X, the timing relay 70T, the door relay 40, the door-control relay 45, the door-close relay DC, the door-open relay DO, the detector relay SR, the time-delay relay SRT and the expediter relay 300. Energy for the various circuits is derived from direct-current buses L-{ and L.

Although various motor control circuits may be employed, it will be assumed that a control circuit of the variable-voltage type is employed. By inspection of Fig. 2, it will be noted that the armature 15A of the driving motor 15 and the armature 29A of a direct-current generator 29, together with a series field winding 29B for the generator, are connected in a series or loop circuit. The field winding 15B for the driving motor 15 is connected directly across the buses L+ and L.

The magnitude and direction of energization of the driving motor 15 are controlled by the direction and magnitude of the energization of a separately-excited field winding 29C provided for the generator 29. It will be understood that the armature 29A of the generator is rotated at a substantially constant rate by a. suitable motor MO which may be a polyphase induction motor energized from a suitable source through a switch MOS. Contacts MOSI are illustrated and are operated by the switch to closed position only when the motor M0 is conditioned to run. For present purposes, it will be assumed that operation of the switch MOS to closed position also closes the contacts MOSl.

.When the elevator car A is conditioned for up travel, the generator field Winding 29C is connected across the buses L{, L through make contacts U2 and U3 of the up switch. When the elevator car A is conditioned for down travel, the generator field winding 29C is connected across the buses through the make contacts D2 and D3 of the down switch. The energizing circuit for the field winding may include a resistor R1 which is shunted by make contacts V1 of the speed relay V. By inspection of Fig. 2, it will be observed that the contacts U2, U3, D2 and D3 constitute in effect a reversing switch for controlling the direction of energization of the field winding. The resistors R1 and the contacts V1 are provided for controlling the magnitude of energization of the field winding.

The speed relay V may be energized through either of two circuits. One of the circuits includes make contacts U4 of the up switch U, a limit switch 30 which is normally closed and which is opened as the elevator car A nears the upper limit of its travel and the break contacts E1 of the slowdown inductor relay ,E. The other circuit is completed through make contacts D4 of the down switch D, mechanical limit switch 31 which is normally closed and which is opened as the elevator car nears the lower limit of its travel in the down direction, and break contacts E2 of the slowdown inductor relay.

As previously pointed out, the brake 17 normally is spring-biased into engagement with the brake drum 16 and is released by energization of a brake coil 17B. The coil may be energized either through make contacts U1 of the up switch U or through make contacts D1 of the down switch D.

In order to energize the car-running relay M, certain safety devices 33 must be in their safe conditions. Such safety devices may include switches which are open when the doors of the elevator car and the associated hoistway doors are open, and which are closed when the doors are closed to control the door relay 40. Such safety devices are well known in the art. The car-running relay M may be energized through either of two circuits. One of the circuits includes the make contacts 80-1 of the starting relay 80, make contacts W1 of the up-preference relay W, break contacts Fl'of the stopping-inductor relay, normallyclosed contacts of a mechanical limit switch 34 which are opened when the car nears the upper limit of its travel, and the coil of the up switch U. When energized, the up switch U closes its make contacts US to complete a holding circuit around the contacts 80-1 and W1.

The second circuit for energizing the car-running relay M includes the contacts 80-1 of the starting relay, make contacts X1 of the down-preference relay X, break contacts F2 of the inductor stopping relay, normally-closed contacts of a mechanical limit switch 35 which are opened as the elevator car nears the lower limit of its travel in the down direction and the coil of the down switch D. When the down switch D is energized, make contacts D are closed to provide a holding circuit around the contacts 80-1 and X1.

Before the holding relay G and the inductor relays E and F can be energized, make contacts M1 of the carrunning relay must be closed. In addition, any one set of make contacts J1 of the reversal relay, TTl of the car-call stopping relay, and K1 of the floor-call stopping relay must be energized. A holding circuit around these contacts is established upon closure of the make contacts G1. Energization of the inductor stopping relay F further requires closure of the break contacts V2 of the speed relay.

If the break contacts J2 of the reversal relay are closed, the up-preference relay W is energized only if the elevator car is not operating in the down direction (break contacts D6 are closed); the elevator car is not conditioned for down travel (break contacts X2 are closed); and normally-closed contacts of a mechanical limit switch 36 are closed. The mechanical limit switch 36 is opened as the elevator car reaches its upper limit of travel. Make contacts M7 of the running relay shunt the contacts J2.

Energization of the down-preference relay .X requires closure of the break contacts U6 of the up switch, closure 10 of the break contacts W2 of the up-pr'eference relay, and closure of the normally-closed contacts of a mechanical limit switch 37. The mechanical limit switch 37 is open when the elevator car A is adjacent the first or dispatching floor.

The doors for the elevator car A are controlled by a door-control relay 45. For this relay to be initially energized, and assuming that the manual switches 64 and are open, the break contacts N1 and TN1 must be closed to indicate that the elevator car is not being loaded at a terminal floor. Break contacts 70HT2 must be closed to indicate that non-interference time allowed for a corridor or floor call has elapsed or the switch 64 must be closed. In addition, the break contacts 70T1 must be closed to indicate that the general non-interference time has expired. The switch SE1 must be closed to indicate that the safety edge SE of the door is not deflected. The make contacts SR1 must be closed to indicate that no object is positioned in the closing path of the door. Finally, the break contacts 70-1 must be closed to indicate that an auxiliary or shortened non-interference time has expired. When the relay 45 picks up, it closes make contacts 45-1 to partially complete a holding circuit for the relay.

If the switch 90 is closed, the energization of the relay 45 is further controlled by two circuits, one containing the switch M081 and make contacts 45-4. The remaining circuit contains a cam-operated switch 68 which is open only when the elevator car is at the lower terminal floor, a switch T S1 which is open only when the elevator car is assigned for down peak operation and break contacts NUl of a timing relay.

Should the safety-edge contacts SE1 be held open for an unreasonably long time (a door-hold button could be provided to control the relay 45 in a similar manner) or should the beams of light across the doorway be interrupted for an unreasonably long time, the break contacts NUAl close to establish with the contacts T N1 and N1 an energizing circuit for the relay 45.

The door-control relay 45 controls the energization of the door-close solenoid DC and the door-open solenoid DO. If the contacts 45-2 of the door-control relay are closed, and the break contacts 40-2 are closed, the solenoid DC is energized. The contacts 40-2 are closed when the door of the elevator car A or an associated hoistway door is away from its closed condition. If a manual switch 64A is open the energization of the solenoid DC also is controlled by the contacts SE3 and SEA2 in parallel.

If the door-control relay 45 is dropped out, the make contacts 45-3 are closed to complete with the switch 38 .an energizing circuit for the door-open solenoid DO. Theswitch 38 is a limit switch which is normally closed and which is opened as the door reaches its fully-open positi-on.

The timing relay 70T is connected for energization by make contacts M5 of the car-running relay. The energizing circuit is completed through break contacts 300-1 of an expediter relay. It will be noted that a resistor R2 is connected across the timing relay 70T and the contacts 300-1. If the timing relay is energized and the contacts M5 thereafter open, the resistor R2 delays the dropout of the timing relay 70T for a suitable non-interference time, such as 5 seconds. If the contacts 300-1 open, the relay 70T drops out promptly.

The detector relay SR is controlled by the make contacts P-Rl-l and PRZ-l These contacts are closed respectively .as long as the photocells PCI and PC2 (Fig. l) are illuminated by their respective radiant energy bears. The contacts may be bypassed by operation of a manual switch 62.

Break contacts SR2 and SR3 of the relay SR respectively control the energization of the time delay relay SRT and the expediter relay 300. The time delay relay SRT may have a time delay in dropout of the order of onehalf second when shunted by the entire resistor RES. If a portion of the resistor is shunted through the loadweighing switch LW2 and the manually-operated switch MS, the time delay in drop-out of the relay SRT is increased to a larger value such as one and one-half seconds. The switch LW2 is closed only when the elevator car A carries in excess of a predetermined load which for present purposes is assumed to be 80% of rated cap-aci-ty.

If the elevator car A is answering a floor call the make contacts 438-1 of the floor-call detector relay 438 are closed to complete with a manually-operated switch MSll a circuit shunting a portion of the resistor. This circuit increases the time delay in dropout of the relay SRT over that provided by the entire resistor RES to a new value which may be of the order of nine-tenths of a second.

The fioor-call-detector relay 438 is initially energized through a manually-operated switch M82 and through make-contacts K3 of the floor-call stopping relay K. When it picks up, the relay 438 closes make contacts 433-2 to complete with the break contacts V3 of the speed relay V a holding cincuit around the contacts K3. For the present it will be assumed that the switches MS, M51 and M52 are all open.

The expediter relay 300 also may be energized by closure of contacts 51. These contacts may be arranged to close whenever a car call is registered in the elevator car A for the purpose of expediting departure of the olevator car from a floor at which it is stopped. For pres- A ent purposes it will be assumed that the contacts 51 represent a push button which is located in the elevator car A and which is operated to expedite departure of the elevator car from a floor.

Although the lamps LAl and LAZ of Fig. 1 may be continuously illuminated, they are illustrated in Fig. 2 as illuminated through break contacts M6 of the car-runing relay M.

FIGURE 3 Fig. 3 illustrates additional circuits for con-trolling door floor a mechanical switch 69 may be operated at such floor to modify the dropout time. In the present case the switch closes to shunt a portion of the timing resistor R3 in order to increase the dropout time to say three seconds.

Make contacts 70HT1 and SRT]. in parallel control the energization of an auxiliary relay 70.

Make contacts SR4 control the energization of a timing relay NU. This relay has .a time delay in dropout (determined by a resistor R4) which may be of the order of four seconds.

Make contacts SR5 of the detector relay SR and the contacts SE2 operated by the safety edge SE control in part the energization of .a timing relay NUA which has a time delay in dropout of say twelve seconds as determined by a resistor R5. If the relay NUA is dropped out, opening of make contacts LWAl drops out the relay promptly.

The timing relay LWA is energized through any of four paths. One path contains the break contacts LW of the load weighing switch LW. A second path contains break contacts of a switch 68A which is closed only when the elevator car is at the bottom terminal floor and contacts T53 which are closed only during down peak periods. The third path has contacts of a mechanical switch 6813 which is closed only when the elevator car is away from the terminal floors and contacts T84 which are closed only during up peak periods. The fourth path contains a limit switch 38A which is open only when the door is open.

The car-call push buttons to Sc normally are biased into their open positions against a set of back contacts 20x to Sex. Each of the push buttons is provided with a holding coil 2cc to See, which is effective for holding the associated push button in its operated condition following a manual operation of such push button. To this end, the push buttons may be made of magnetic material. Such construction of the push buttons is well known in the art.

Each of the push buttons 2c to ie has front contacts controlling the connection of contact segments to the bus L+. When operated, the push button 20 connects the contact segments :12 and I12 to the bus L+. The push buttons and 4c similarly connect contact segments for the third and fourth floors to the bus L+. Inasmuch as the elevator car is assumed to stop at the fifth floor or upper terminal floor at all times during up travel, the contact segment a5 is permanently connected to the bus L+. Similarly, during down travel, the elevator car A always stops when it reaches the first floor, and the contact segment 121 for the first floor is permanently connected to the bus L+.

it will be understood that the contact segments a2 to :15 are arranged in a row on the floor selector 19 of Fig. 1 and are successively engaged by a brush 23 as the elevator car moves from its lower limit to its upper limit of travel. In a similar manner, the contact segments 124 to hit are arranged in a row in the order of the floors for successive engagement by a brush a as the elevator car moves from the upper terminal to its lower limit of travel.

During up travel of the elevator car A, the car-call stopping relay TT is connected between the brush 23 and the bus L through make contacts W3 of the up-preference relay and make contacts M3 of the car-running relay. Consequently, when the brush 23 reaches one of the contact segments a2 to a5 which is connected to the bus L+, the car-call stopping relay TI is connected for energization across the buses L-land L for the purpose of stopping the elevator car at the next floor reached by the car. As the elevator car stops, the brush 23 preferably passes slightly beyond the associated contact segment.

When the elevator car A is conditioned for down travel, the car-call stopping relay TT is connected between the brush 40a and the bus L- through the make contacts X3 of the down-preference relay and the make contacts M3 of the car-running relay. Consequently, when the brush 40a reaches one of the contact segments I14 to hl which is connected to the bus L+, the car-call stopping relay TT is energized to initiate a stopping operation of the elevator car at the next floor reached by the car. As the elevator car stops, the brush 40a preferably passes slightly beyond the associated contact segment.

The coils 2cc to Sec are connected in series for energization either through make contacts W4 of the uppreference relay or make contacts X4 of the down-preference relay. When the elevator car reverses its direction of travel, the make contacts W4 and X4 both are momentarily opened to deenergize the associated holding coils for the purpose of resetting the car-call push buttons.

Each of the car-call buttons when operated opens an auxiliary set of normally-closed contacts 20x, 30x and 40x respectively. These are employed in a high call circuit which will be discussed below. A set of contacts 50.x and a holding coil See also are provided for the fifth floor.

When the down floor-call push button 2D is operated, the down floor-call storing relay 2DR is connected therethrough across the buses L+ and L- for energization. Upon energization, the relay closes its make contacts 2DR1 to establish a holding circuit around the push button. The contact segment f2 now is connected (and corresponding contact segments for the remaining elevator cars are connected) through the contacts 2DR1 to the bus 'L+. The contact segments f4 and f3 similarly are connected to the bus L+ by operation of the down floor-call push buttons 4D and 3D. The contact segments f4, f3 and f2 for the fourth, third, and second floors are positioned in a row on the floor selector 19 of Fig. 1 for successive engagement by a brush 58 as the elevator car A moves from the upper terminal in a down direction.

The floor-call stopping relay K is connected between the bus -L-+ and the brush '58 through make contacts X of the down-preference relay. Consequently, if the elevator car A approaches the second floor during a down trip while a down floor call is registered for such floor, the engagement of the contact segment f2 by the brush 58 completes an energizing circuit for the floor-call stopping relay K.

Each of the down floor-call storing relays 4DR, 3DR and 2BR has an operating coil and a cancelling coil, respectively, 4DRN,.3DRN and 2DRN which is energized in opposition to the enerigzation of the operating coil. The cancelling coil 2DRN is connected between a contact segment g2 (and similar contact segments Bg2 etc. for the other elevator cars) and the bus L+ through the make contacts 2DR1. As the elevator car A reaches the second floor, the following energizing circuit for the cancelling .coil is established:

L+, 2DR1, ZDRN, g2, 59, X6, M4, L

Energization of the coil 2DRN opposes energization of the relay by the operating coil and resets the relay. It will be understood that the contact segments g4, g3 and g2 are arranged in a row for successive engagement by the brush 59 as the elevator car proceeds downwardly from the upper terminal floor to control the energization of the cancelling coils 4DRN, 3DRN and 2DRN.

The down floor-call storing relays all cooperate with the brushes 58 and 59 in substantially the same manner to control the energization of the floor-call stopping relay during down travel of the elevator car.

When the up floor-call push button 2U is operated, the up floor-call storing relay 2UR is connected for energizati-on therethrough across the buses L+ and L-. Upon operation, the relay closes its make contacts 2UR1 to establish a holding circuit around the push button 2U.

I As a result, a contact segment b2 is connected (and contact segments Bb2 etc. for the other elevator cars are connected) to the bus L+ through such make contacts.

As the elevator car during up travel approaches the second floor, the brush 60 engages the contact segment b2 to establish the following energizing circuit for the floor-call stopping relay:

L+, 2UR1, b2, 60, W5, K, L-

This conditions the elevator to stop at the second floor. As the elevator car stops at the second floor, a brush 61 engages the contact segment 02 to establish the following circuit for the cancelling coil of the storing relay 2UR:

L+, 2UR1, ZURN, c2, 61, W6, M4, L.

Such energization of the cancelling coil results in resetting :of the storing relay which has its main coil acting in opposition to the cancelling coil. The up floor-call push buttons 3U and 4U similarly control the associated storing relays and contact segments. It will be understood that thecontact segments 02, c3 and c4, and contact segments b2, b3 and M are arranged in rows on the floor selector for engagement successively by the brushes 61 and 60, as the elevator car A proceeds upwardly.

FIGURE 4 In Fig. 4 a starting relay 80, a dispatching device which normally controls the lower terminal dispatching of 14 the elevator cars employed in the system, and a reversal relay J are illustrated.

The starting relay 80 can be energized only if the timing relay 70T is deenergized and dropped out to close its break contacts 70T2. If additional non-interference time is allowed for a corridor or floor call, the manual switch 65 is open and the break contacts HT3 of the timing relay also must be closed to permit energization of the relay 80. When the elevator car is positioned at the lower dispatching floor, the energizing circuit for the starting relay normally is completed through the make contacts S1 of an auxiliary starting relay. At the upper terminal or dispatching floor, make contacts TTSl may operate in a manner similar to the operation of the contacts S1 for the lower dispatching floor to start the elevator car from the upper terminal floor. Between the dispatching :fioors, the make contacts S1 are shunted by the contacts of a mechanical switch 63. This switch is cam operated to open when the elevator car is adjacent the upper terminal ordispatching floor and the lower dis-.

patching floor. For all other positions of the elevator car A, the switch 63 is closed.

The selection and timing mechanism include as one component a motor 71 which operates substantially at constant speed. This motor may be of any suitable type, but for present purposes it will be assumed that the motor is a squirrel-cage alternating-current motor which is energized from a suitable source of alternating current. The motor 71 is connected through a spring-released electromagnetically applied clutch 72 to a cam 73 having a protuberance for successively operating mechanical switches Y, BY, CY and DY which are associated with the respective elevator cars. The electromagnetic clutch can be energized only if one or more elevator cars are located at the dispatching floor which is assumed to be the first floor (one or more of the contacts L1, BLl, CLl, DL1 are closed), and if no elevator car has been selected as the next car to leave the dispatching floor (break contacts N2, BN2, CN2 and DN2 all are closed).

The motor 71 also may be coupled through a springreleased el-ectromagnetically applied clutch 74 to a cam 75 which is biased towards a predetermined position by a spring 76. The cam 75, when coupled to the motor 71, is rotated against the bias of the spring to close normally-open contacts 77 a predetermined time after the cam 75 is coupled to the motor 71. The clutch 74 can be electrically energized only it" no elevator car is being started (break contacts S2, BS2, CS2 and DS2 are closed). and if the break contacts 1S1 of the holding relay 18 are closed. The holding relay 15 is energized upon closure of the contacts 77 to close its make contacts 182 for the purpose of establishing a holding circuit around the contacts 77.

The presence of an elevator car at the dispatching floor is determined by the energization of a car-position relay for each of the elevator cars. Thus, a car-position relay L for the elevator car A is energized when the brush 24 engages the contact segment e1.

The brush 24 is operated by the fioo-r selector for the elevator car A to engage the contact segment e1 when the elevator car is at the dispatching floor.

If the elevator car A is at the dispatching fioor (make contacts L2 are closed), it it has been selected as the next car to leave the dispatching floor (switch Y is closed). and if it is not being started (break contacts S3 are closed), the loading relay N for the elevator car A is energized. The loading relay may be employed in a conventional way to permit loading of the elevator car A. For example, the loading relay when energized may operate a loading signal, such as a lamp, which indicates that passengers may enter the elevator car. Conveniently, the loading relay N when energized opens the normallyclosed doors of the elevator car A to permit entry of passengers into'the elevator car.

After the expiration of a time sufficient for cam 75 to close the contacts 77 and energize the relay IS, the make contacts 153 close to complete the following circuit:

L+, L2, S, N3, 183, L

The relay S when energized closes its make contacts S4 to establish a holding circuit around the contacts N3 and 183, and starts the elevator car A from the dispatching floor.

If the elevator car is loaded before expiration of the interval measured by the relay 18 it may be advisable to expedite departure of the car. To this end a manual switch 99 may be closed to connect the relay 28 for energization through any of four parallel circuits, one for each of the elevator cars. The circuit for the elevator car A includes break contacts 70T3 of the non-interference relay, make contacts N4 of the loading relay and a switch LW1 which is closed only when the load in the elevator car exceeds say 80 percent of rated capacity. Thus if the elevator car A is selected as the next car to leave the terminal floor (contacts N4 are closed), if the non-interference time has expired (contacts 70T3 are closed) and if the elevator car is fully loaded (switch LW1 is closed) the relay picks up and closes its contacts 2S1. Since the contacts 251 shunt the contacts 183, prior closure of the former contacts expedites dispatch of the elevator car.

Fig. 4 also discloses a reversal relay I which is connected between a brush 66 and the bus L+ through a manually-operated switch 67 and make contacts W7 of the up-preference relay. The brush 66 and an associated row of contact segments k2, k3 and k4 are included in the floor selector of Fig. 1. The contact segments are associated with a call circuit which includes break contacts of the call registering relays and the contacts 3CX, 4CX and SCX associated with the car-call push buttons. By tracing this circuit in Fig. 4 it will be noted that the bus L+ is connected to the contact segment k2 through the following circuit:

are located between the contact circuit segments k2 for t the second floor and the bus L+.

The contact segment k3 is connected to the call circuit between the contacts 3UR2 and 3DR2. Consequently, contacts of all call registering relays or car-call push buttons requiring travel of the elevator car above the 4 third floor are located between the contact segment k3 for the third floor and the bus L+. In an analogous manner, the contact segment k4 for the fourth floor is connected to the call circuit at a point between the contacts 4UR2 and 4DR2. Such call circuits are well known in the art.

Operation In order to explain the over-all operation of the elevator system, it will be assumed first that the elevator cars are at the first or dispatching floor when the system initially is energized. The cars are conditioned for operation in the up direction. For example, the switches MOS and MOS are closed and the elevator car A has its up-preference relay W energized. Consequently, make contacts W1, W3, W4, W5, W6, W7 of the relay are closed, whereas break contacts W2 of the relay are open.

The switches 90 (Fig. 2), 63A (Fig. 3) and 67 (Fig. 4) are assumed to be open. Since the cars are at the first floor, the switch 63 also is open. The timing relay 70T is assumed to have timed out. The relays SR, 45 and 40 1 5 are picked up and the elevator car doors are closed. Switches 64A and 68A are closed and switch 68B is open. Switches MS, MS]. and M82 (Fig. 2) are open.

The motor 71 (Fig. 4) is energized to rotate at a substantially constant rate.

Inasmuch as the elevator cars are assumed to be at the dispatching floor, the car-position relays L, etc. are energized.

As a result of its energization, the car-position relay L closes its make contacts L2 to prepare certain circuits for subsequent energization. In addition, the make contacts L1 close to complete the following circuit for the clutch 72.

L+, L1, 72, N2, BN2, CN2, DN2 L The clutch now couples the motor 71 to the cam 73 for the purpose of successively closing and opening the associated mechanical switches. It will be assumed that the first switch reached by the cam is the switch Y for the elevator car A. Closure of this switch completes the following energizing circuit for the loading relay of the elevator car A:

L+, L2, N, S3, Y, L-

The loading relay N upon energization initiates opening of normally-closed doors of the elevator car A to permit intending passengers on the dispatching floor to enter the elevator car. Such opening is eifected by opening of contacts N1 (Fig. 2) to deenergize the door-control relay 45. This relay opens its contacts -1 and 45-2 without immediate effect on system operation. However, closure of contacts 45-3 energizes the solenoid D0 to open the doors. In opening, the door opens its set of contacts 33 to deenergize the door relay 40 which opens its contacts 40-1 and closes its contacts 40-2 without immediate effect on system operation. When it reaches open position, the door opens limit switch 38 to deenergize the solenoid DO.

Opening of the break contacts N2 (Fig. 4) deenergizes the clutch 72. Consequently, the cam 73 is uncoupled from the motor 71. Finally, the make contacts N3 close to prepare the starting relay S for subsequent energization.

When the system was placed in operation, the clutch 74 was energized through the circuit:

L+, 181, 74, S2, BS2, CS2, DS2, L

As a result of its coupling to the motor 71T, the cam 75 rotates against the bias of its spring 76 until at the expiration of the time interval allowed for loading elevator cars the contacts 77 close. Closure of these contacts completes the following circuit:

L+, IS, 77, S2, BS2, CS2, DS2, L-

The energized relay 1S closes its make contacts 182 to establish a holding circuit around the contacts 77. The break contacts 181 open to deenergize the clutch 74, and the spring 76 now rotates the cam to its starting position. Also, the make contacts 153 close to energize the auxiliary starting relay S through the following circuit:

L+, L2, S, N3, 183, L-

Energization of the auxiliary starting relay S closes the make contacts S4 to establish a holding circuit around the contacts N3 and 183. Break contacts S3 open to deenergize the loading relay N. Break contacts S2 open, and this opening causes relay 15 to drop out. This has no immediate ff6Ct on the system operation.

The loading relay when deenergized opens its make contacts N3 without immediate effect on the operation of the system. In addition, break contacts N2 close to prepare the clutch 72 for subsequent energization.

The deenergization of the loading relay further closes break contacts N1 (Fig. 2) to complete with the contacts 1, SR1, 7lT1 and TNl an energizing circuit for the steam 17 door-control relay 45. The latter relaycloses its make contactsv 45-1.. and. opensitsibrealc contacts 45-3 without immediate effect on system: operation. However, closure of makev contacts 45-2 completes with the contacts 40-2 an energizing circuit for the door-close solenoid DC, and the: door now starts to close. If the switch 62 is open and a passenger is in the closingpath of. the door, he interrupts one of' the beams of. radiant energy and' one of the sets of contacts PRl-l or? PR2-2 opens to demergizei the detector relay SR. Thisi relay then opens its: make contacts SR1 todeencrgize 'the door-control relay 45'. The latter opens its contacts: 45-2 to deenergize the door-close solenoid and closes its contacts 45-3 to" energize the door-open solenoidfor'the purpose of reopen'- ingt axpartly-cl'osed. door. The detector. relay also closes itsbreak: contacts: SR2" and. SR! to. energize the relays SRT'and 300. The-energization ofv the relay 300 has no effect at'this time on the operation of the system butv the energization of the relay SRT clos'e's make contacts SRTl. to pick up the timing relay 70 (Fig: 3.). This relay opens its break contacts" 70*1. After-tthe passenger clears the door closing patli,-.the detector relay SR picks up to? close" its make contacts: SR1; and open its break. contacts SR2 and SR3; The: resultant dropout: of the relay 300 has no eifect at this time on the system operation. However,

the openingrof contacts SR2 starts a timing out operation of: the relay SRT. After' the expiration of its time delay", such as' one-half second, therelay SRT drops out to open its contacts SRIEI and such opening drops out relay 70. The why 70 closes its break contacts Ill-Ito complete a circuit. for the relay- 45;

The operationszo'f relays N11,. NUZA and LWA will be discussed. below.

In some cases, it is desirable to prevent a reopening of the" door by the relay SR. Insu'chi. a case, themanu'allyoperatedswitch 90may be closed to=connect make contacts 45-4 of the door-control relay and the switch MOST around the contacts SR1 and 70 -1. When the door-control: relay picksup, the resulting" closure of its" contacts 45-41 assures door. closure despite subsequent dropout ofthe relay. SR, provided that the switch M081 isclosed to indicate that the motorgenerator set is'run ningt. For the following discussion, the switch-90 isconsidered to be open; Even with the switch 90 closed, if the door actually encounters a person, the safety edge would open the switch SE1 to" deen'ergiz'e the relay 45' andreopen the door.

It will; be assumed however that? no person is in the Upon closing, theclosing path and that the door closes; door closes its switch 33 to' complete an energizing circuitfor the'do'orrelay- 40' which clos'es' its make contactsthedoor' relay (Fig. 2) coupled with closure of the make" contacts 80--1 ofithe' starting relay completes the following circuit for the up switclf-and the" car running relay:

The energized up' switch U close's its make contact'Ul' to release the'brake I7, and contacts U2 andU3'close to energize the generator fieldwinding. 29C with proper polarity for up travel'of the elevatorcar. Make contacts U4 close to complete through the limit switch 30 and the contacts E1 an energizing circuitfor the speed'relay V. The speed relay closes its make contact VI toshu'nt" the resistor Rl and condition the elevator 'carA for fiill speed operation" in the' up di'rection2 Also, the speed 18 relay opens its break contacts V2 to prevent energ'ization: 'thcrethrou'gh of the stopping inductor relay F. Un der the assumed conditions, opening of the contacts V3 has no effect on system operation.

Returning to the up switch U, it will he noted that closure of the make contacts U5 establishes a" holding circuit around the contacts 80-1 and W1. Opening of the break contacts U6 prevents energization therethrough ofth'e down preference relay; The elevator car A new is'in condition for full speed operation in the up direction and departs from the dispatching floor.

It will be recalled that the car-running relay M was energized with the up switch U. The car-running relay Closed itsmake contacts M1, M3, M4 and M7 (Fig. 3') without immediate effect on the operation of thesystem; However, closure of the make contacts- M2 (Fig. 2')' completes with the contacts 45-1 and- N1 a'holding circuit for the door-control relay 45. Opening of break contacts M6 deenergizes the lamps LA-1' and LA2. Closure of the make contacts M5 energizes the timing relay T..-- This relay opens its break contacts 70T2 (Fig.4) which causes the starting relay to become deenergized. Opening of break contacts 70T1' (Fig; 2) does not immc diately affect system operation. I

It will be assumed now that the passenger in the elevator car operates the car-call push button 3c (Fig. 3)" to register a car call for the third floor. Such operation-- opens the contacts 30x without immediate effect on thesystem and connects the contact segments a3 and h;3 to thebus L+. As the elevator car nears the third floor; the brush 23 engages the contact segment a3 to complete the followingcircuit for the car-call stopping relay 1+, 3a,- a3, 23; W3"; TT. M

The car-call stopping relay now closes its make contacts (Fig- 2)'- to energize the holding relay G and the slowdown inductor relay B through the closed c'ontacts M1. Energization of the holding relay G completes through the make contacts G1 a holding circuit around the contacts 'ITI.

When the elevator car A in its upward travel reaches the inductor plate UEP (Fig. 1) for the third floor, the break contacts E1 are opened to deenergize the speed re- 'lay'V (Fig. 2). The speed'relay opens its break contacts V1 to'introduce' the resistor R1 in series'with the generator field winding 29C. The resultant reduction infield current slows the elevator car to a landing speedi In addition,- thespeed relay V closes its break contacts V2" to completethroughthe contacts G1 and M1 an energiz ing circuit for the' stopping inductor relay F. Closure of" break contacts V3has no efiect on the system.

Shortly before the'elevator car A in its continued up' ward movement at the landing speed" reaches the third floor, the inductor plate UFP for the third floor is ad jacent the stopping inductorrelay and'completes a-n iagnetic circuit which results in opening of the conta'ctsFli Opening of the contacts F1 (Fig; 2) deenergi zcsthe up" switch U and'the car-running: relay M.

The up switch U opens its make contacts Ulito deenergize" the" brake 1'7, andthe brake'is'promptly'forced a gainst'thebrake drum 16-by its associated spring; Con tactsUZ and'US' open to deenergize the generatorfield' winding" 29C. Consequently, the elevator car A stops accurately atthe-third floor. Opening'of the make com tacts U4 and US andclosure of thehreja'k contacts U6 have no immediate effect on" the" operation of the sys' tern. Astheelevator car come's'to'astop the'b'rush' 23" may pass the contact segment for a slight distance to deenergize the relay TI. 7

The" previously-mentioned deenergization' of the car'- runningrelay resultedin opening of theniake contacts to deenergize the inductor relays E an'd'F andthe" h'olding relay G; The holding relay G opened its make contacts- G1" without immediately aifecting the operation of the system? The car-running relay also opened its make contacts M5 to start a timing-out operation of the timing relay 70T. Contacts M5 preferably open with a slight time delay to assure prior closure of contacts 300-1. This realy 70T has a time delay in drop out sufiicient to permit discharge of passengers or entry of passengers into the elevator car A. For example, a time delay of live seconds may be employed. Opening of the make contacts M3 and closure of the break contacts M4 have no immediate effect on the operation of the system. Closure of contacts M6 illuminates the lamps LA1 and LA2, and these illuminate their associated photocells to close contacts PR1-1 and PRZ-l which pick up relay SR. The pick up of relay SR and the resulting deenergization of relays SRT and 300 have no immediate effect on the operation. However, the relay SRT starts to time out. Opening of make contacts M2 deenergizes the door control relay 45 and this relay opens its make contacts 45-1 and 45-2 without immediate effect on system operation. However, closure of break contacts 45-3 completes with the switch 38 a circuit for the door-open solenoid DO and the door now opens. In opening, the door opens its switch 33 to deenergize the door relay 40 without immediate effect on system operation.

Let it be assumed that instead of a car call, an up floor call was registered for the third floor by operation of the push button 3U (Fig. 3). Such operation energizes the up floor call storing relay 3UR which closes its make contacts 3UR1 to establish a holding circuit around the push button. The contacts 3UR1 also serve to connect the contact segment b3 and corresponding contact segments for the remaining elevator cars of the system to the bus L+. Opening of contacts 3UR2 and 3UR3 does not affect the operation of the system at this time.

As the elevator car approaches the third floor, the brush 60 engages the contact segment b3 to energize the floorcall stopping relay K through the following circuit:

L+, 3UR1, b3, 60, W5, K, L

Upon energization, the floor call stopping relay closes its make contacts K1 (Fig. 2) to energize through the contacts M1 the holding relay G, the slowdown inductor relay E and the stopping inductor relay F. These relays operate in the same manner previously discussed to stop the elevator car accurately at the third floor. Contacts K2 of the floor call stopping relay also close to complete with the contacts J3 an energizing circuit for the relay 70HT. The latter relay 70HT closes its make contacts 70HT1 and opens break contacts 70HT2 and 70HT3 without immediately effecting the operation of the system. Under the assumed conditions, closure of contacts K3 and pick up of relay 438 has no effect on system operation.

As the elevator car A slows down to stop at the third floor, the brush 61 engages the contact segment 03 to complete the following cancelling circuit:

It will be recalled that the break contacts M4 close as the elevator car stops at the third floor. As a result of its energization, the cancelling coil 3URN resets the up floor-calling storing relay for the third floor. Such reset is accompanied by deenergization of the floor-call stopping relay K which opens its make contacts K1 and K3 without affecting system operation. However, the opening of the make contacts K2 starts a timing out operation of the relay 7 HT.

Referring to Fig. 4, it will be recalled-that the mechanical switch 63 is open only at the dispatching-floor and the upper-terminal floor positions of the elevator car. Since the elevator car is now at the third floor, the switch 63 is closed. Consequently, as soon as the timing relay 70T drops out, the break contacts 70T2 close to complete an energizing circuit for the starting relay 80.

20 This operates in the manner previously discussed to start the elevator car upwardly. In this way, the elevator car Acontinues to the upper terminal floor, answering all registered car calls and all registered up floor calls during its upward trip.

As previously pointed out, the drop out of the timing relay 70T provides a non-interference time which may be of the order of 5 seconds. If desired, a longer noninterference time may be provided for a stop made in response to a corridor or floor stop. For example, assume that the switches 64 (Fig. 2) and 65 (Fig. 4) are open and that the relay HT has a delay in drop out of say six seconds. Under such circumstances, the relay 45 (Fig. 2) cannot be energized to close the door and the' relay (Fig. 3) cannot be energized to permit starting of the car until a non-interference time of six seconds has elapsed to permit closure of contacts 70HT2 and 70HT3. It will be assumed, however, that the switches 64 and 65 are closed.

If a passenger leaves the elevator car at the third floor promptly, say, in 1 second, it follows that a substantial and unnecessary delay in the departure of the elevator car would be imposed if the relay 70T is allowed to complete its normal timing interval before the car departs from the third floor.

In the present case, the departure of the elevator car is expedited to an extent dependent on whether the elevator car is answering a car call or a floor call. By reference to Fig. 1, it will be noted that when the car stops for a car call and the passenger leaves the elevator car at the third floor, he temporarily interrupts the beams of radiant energy directed towards the photocells PC1 and PC2. Such temporary interruption temporarily interrupts and drops out the relay-s PR1 and PR2.

Referring to Fig. 1 and Fig. 2, it will be noted that the drop out of the relays PR1 and PR2 opens make contacts PRl-l and PR2-1 to deenergize the detector relay SR. The detector relay opens its make contacts SR1 to prevent energization therethrough of the door-control relay 45 as long as the passenger stands inthe closing path of the door. In addition, break contacts SR2 and SR3 close to energize the time delay relay SRT and the expediter relay 300. Energization of the time delay relay SRT results in closing of the make contacts SRTI and pick up of the relay 70 without immediately affecting the operation of the system. The relay 70 opens its break contacts 70-1. The expediter relay 300 opens its break contacts 300-1 to instantly drop out the timing relay 70T. Since the timing relay is now dropped out, it closes its break contacts 7011. However, since the contacts SR1 and 70-1 are open, the door-control relay 45 cannot be energized. In addition, break contacts 70T2 (Fig. 4) close to complete with the switch 63 an energizing circuit for the main starting relay 80. The main starting relay 80 closes its make contacts 80-1 (Fig. 2) without immediate effect on the operation of the system. Contacts SR4 and SR5 (Fig. 3) open to start timing out operations of the relays NU and NUA.

It will be assumed that the passenger passes promptly through the doorway and that the beams of radiant energy are promptly reapplied to their associated photocells. As a result of such reapplication, the make contacts PR1-1 and PR2-1 reclose to energize the detector relay SR. This relay opens its break contacts SR3 to deenergize the expediter relay 300, but such deenergization has no immediate effect on the operation of the system. Opening of the break contacts SR2 initiates a timing out operation of the the time delay relay SRT. Closure of the make contacts SR1 has no immediate effect on the energization of the door control relay 45 for the reason that the contacts 70-1 are still open. Closure of make contacts SR4 and SR5 (Fig. 3) reenergizes the relays NU and NUA.

Upon the expiration of the one-half second time delay in dropout of the relay SRT, this relay drops out to open 21 its. make contacts SRT 1. The auxiliary relay 70. now closes: itsv break contacts 70-1 to complete the energizingcircnit; for the door-control relay 45. This relay 45. thereupon operates in the manner previously described to initiate a door-closing operation of the door of the elevator car A and the starting of the elevator car A from; the third: floor. It should be. noted that this operation; may save several seconds of time in starting the elevator car from the third floor.

Should another passenger immediately follow the first passenger to. leave the elevator car at the third floor, the radiant energy beams again would be; interrupted to deenergize the detector relay SR. This relay would reclose, its break contacts SR2 to reenergize the time delay relay? SRT. Since the relay SRT has not yet dropped out, the: reenergization thereof occurs before the elevator car door starts to close and delays reclosure of the door for thefull. time delay of the. relay SRT. If a larger number of passengers follow each other out of the elevator car A, it follows that the relay SRT is reset in response to each departure of a. passenger. A similar op erationresults from the successive entry of a plurality of passengers into the elevator car. Following the entry of the last passenger, the relay 45 is operated to close the door and start the elevator car;

The effect of movement of a passenger or an intending passenger out of or into theelevator car located at thethird floor now will be considered for the case in which the elevator carhas stopped at the thirdfloor in response to the floor call. registered by operation of the push button 3U. It will be recalled that if the elevator car. A stopped at the third floor under these conditions, the make. contacts K2 (Fig. 3) closed to energize the timing relay 70HT and then reopened to start a timing out operatibn of the relay. For present. purposes, this relay may havea. delay in drop out of the order of two seconds. When the relay. 70HT was energized, it closed its contacts, 'I'DHTI to assist. in maintaining energized the. auxiliary relay 70. It is assumed that the switch 64 is closedto shunt the break contacts 70HT2.

. If no passenger enters or leaves the elevator car for a periodofitwoseconds, the timingrelay 70HT finally drops outtmdeenergize the auxiliary relay 70. The relay 70 cl'oses its break contacts701 (Fig. 2) but the door control' relay, 45-.cannot yet. be. energized for the reason that the breakcontacts 70T1 of the timing relay 70T are still 12 1,.

If theelevator car remains at the. third floor. for a. total of five seconds without the entry of an intendingpassenger or departure of a passenger from within the elevator car, the timing relay 701 drops out to close its break contacts 70T1 and 70T2 (Fig. 4). This operation of the timing relay initiates the closing. of the door and'the starting of the elevator car from the-third floor in the. manner previously described;

Next let it be assumed that a passenger left the elevator can one second after the elevator car stopped at the third floor. It will be recalled that atthis time thetiming relays70T and. 70HT both are picked up and both are timing out.

Astthcpassenger passes through the doorway he temporarily interrupts the beamsof radiantrenergy directed toward the photocells PCI and PCZ. Consequently, the relays,PR1- and. PR2 temporarily drop out. to interrupt momentarily, the energizing-circuit for the detector relay SR. The detector relay SR. momentarily opens its make contacts SR1 without immediate efiect on the operation of the system. In addition, break contacts SR2 andSR3 close to energize the time delay relay SRT and the expediter relay 300. Opening of the make contacts SR4'and SR5 starts timing out operations of the relays NU and NUA;

7 As a resultof its drop out, the expediter relay 300opens its break contacts 3004 todrop out instantly the timing relay. 70T.v The. resulting closure of thebreak contacts 7013 is, inefiective, for, energizing door. control. relay; 45

for the reason, that thebreak contacts 70-1. of the aux iliary relay 70 are still open. The closure of the break contacts 70T2 (Fig. 4) completes an energizing circuit for the main starting relay However, the main starting relay cannot start the elevator car until the door is closed.

The temporary energization of the time delay relay SRT results in an energizing and timing out of this relay,

inasmuch as this relay is assumed to have a delay in drop out of the order of one-half second. It finally drops out to open make contacts SRTl. Such opening has no effect on the. system for the reason that the make contacts 7 0HT1' are. still closed.

Uponthe expiration of two seconds following the'stopping of'the elevator car at the third floor, the timing relay 70HT, drops out to open itsmake-contacts 70HT1. This deenergizes the auxiliary relay 70 and results in closure of the break contacts 711-1 to: complete the. following circuit:

L+, 701, SR1, SE1, 70Tl, 64, 45, TNI, N1, L-

The door control relay 45 is now energized to. initiate a closing operation of the door and the resultant starting of the elevator car by a sequence which will be clear from the foregoing discussion.

Let it be assumed next that just before the timing relay 70HT timed out a second passenger followed the first passenger out of. the elevator can. This resulted in another temporary interruption of the. beams of. radiant energy directed towards the photocells P01. and PC2 and a temporary drop out of the relaysPRl. and PR2. Consequently, the detector relay SR. again is temporarily dropped out to open itsmake contacts SR1 momentarily and close its break. contacts SR3 momentarily to energize the relay 300. Such, operations have no immediate efiect on the performance of this system. The temporary opening of the make contacts SR4 and SR5 starts a timing out operationof the relays NU and NUA and then reenergizes the relays.

It willbe noted that the relay SR also temporarily energizes the time delay relay SRT and this relay closes its make contacts SRTl just before the make contacts 70HT1 open. Consequently, even though the time period for the timing relay 70 HT has expired, the make contacts SRTI maintain the energization of the auxiliary relay 70 for approximately ahalf second'to permit movement of other passengers through the doorway as required. It will be recalled that the door cannot be reclosed until the auxiliary. relay 70 drops out to close its break contacts 70'1. From the discussion, it should be clear that as long as successive passengers follow each other into or out of the elevator car within one-half. second intervals, the door of the elevator car remains open to permit such movement of the passengers. One-half second after the departure of the last'passenger, the contacts SRTl open to drop out the auxiliary relay 70and permit closure of the elevator car door.

In order to' make the relay NU etfective for controlling the operation of the system, the manual switch may be closed. Such closure conects thev break contacts NU1 of the; timing relay, NU, and contacts of a switchTSl across the contacts SR1 and 70-1.

If a passenger attempts to delay closureof theelevator car door by standing in the path of the beams. of radiant energy directed towards photocells RC1 and PCZ, he also maintains open the make contacts SR4 to permitia timing out operation of the timing relay NU. Upon the expiration of its time delay, which may be of the order of four'second's, this relaycloses its break contacts to complete with the switch TS1 or the switch 68 an energizing circuit for the doorcontrolled relay 45; Under these circumstances; the door promptly starts to close. If the door is provided with a safetyedge and the safety edge encounters the passenger, the switch SE1 opens and initiates a=reopening operation of door. Shouldthe pas 'senger move out of the path of the beams while the door is reopening, the detector relay SR again picks up and closes its make contacts SR4 to energize the timing relay NU. This relay opens its break contacts NUl to prevent energization therethrough of the door control relay. In addition, make contacts SR1 close and break contacts SR2 and SR3 open. Opening of the contacts SR2 initiates a timing out operation of the relay SRT. Onehalf second later this relay drops out to open its make contacts SRTl and deenergize the auxiliary relay 70. The auxiliary relay then closes its break contacts 70-1 to complete an energizing circuit for the door control relay 25 and this initiates a closing operation of the door.

It may be desirable under certain conditions to prevent the timing relay NU from controlling the closure of the elevator car door. Thus, contacts may be included which render ineffective the contacts NUl of the timing relay. For example, it may be undesirable to permit such control by the timing relay NU during a down-peak period at the lower terminal floor. The switch TS may be designed toopen during the down-peak period. It will be understood that during a down-peak period the demand for elevator service is predominantly in the down direction.

For present purposes, it will be assumed that the switch TS is a time switch which opens its contacts during certain periods of the day when down-peak travel is expected. if the time switch is to be effective only at the lower terminal floor, it may be shunted by the mechanical switch 68 which is cam operated to open only at the lower terminal floor and which is closed for all other positions of the elevator car.

Let it be assumed next that the safety edge SE is operated to hold the contacts SE2 open for a period in excess of the dropout time delay of the relay NUA or that a person stands in the paths of the light beams to maintain the contacts SR5 open for such a period. Under such circumstances the relay NUA drops out and closes its contacts NUAl to complete with the contacts TNl and N1 an energizing circuit for the door control relay 45, to initiate a postive door-closing operation. If desired, the dropout of the relay may operate contacts for controlling the door-closing motor or solenoid to close the doors at slower than normal speed and with increased force. If the safety edge SE is released or the person moves out of the paths of the light beams before the door closes, the relay NUA is reenergized and opens its contacts to restore the door control relay 45 to control by the safety edge SE and the light beams. However, if such restoration is not desired the relay NUA may be given sufficient delay in pickup to assure closure of the door.

Even though contacts NUAI are closed, if the switch 64A is open the closure of the door is prevented if both safety edges SE and SEA are operated. Under such circumstances the parallel contacts SE3 and SEAZ are both opened to deenergize the door-close solenoid DC. if either of the safety edges thereafter is. released the door resumes its closing movement.

Under some circumstances the efiiciency of the ele vator service may be improved by expediting the dropout of the relay NUA. Such dropout is expedited by opening of the make contacts LWAl of the time-delay relay LWA.

The time delay relay LWA may have a time delay in dropout of the order of three seconds. If the elevator car is not fully loaded the relay LWA is energized through the load switch LW. if the elevator car is loaded in excess of say 80% of capacity, the load switch LW opens to permit deenergization of the relay LWA. If desired the relay LWA may have an instantaneous dro out when deenergized.

Preferably the deenergization of the relay LWA is prevented while the elevator is at predetermined floors under predetermined traffic conditions. Thus if the elevator car is at the lower terminal floor the switch 68A is closed. If the elevator system at the same time is 24 conditioned to provide down peak service the switch T83 is closed. Since the relay LWA is maintained energized through the switches 68A and T83 the relay is ineffective for shortening the dropout time delay of the relay NUA.

If the elevator car is away from both terminal floors the switch 68B is closed. If the elevator system is conditioned at the same time to provide up peak service the switch T84 is closed. Under these conditions energization of the relay LWA is maintained through the switches 68B and T84, and the relay is ineffective for shortening the dropout time delay of the relay NUA. During an up peak traffic is predominantly in the up direction. Systems for providing specialized elevator service during peak periods are known in the art. For present purposes it will be assumed that a time switch closes contacts TS l during the periods of a day for which up peaks are expected to occur.

Thus if the elevator car is fully loaded at any floor during periods other than up and down peak periods, or if the elevator car is fully loaded at any floor other than the lower terminal floor during a down peak period or if the elevator car is fully loaded at a terminal floor during an up peak period the door will be closed positively three seconds after such full loading occurs.

Positive closing of the door at the lower terminal floor during a down peak period usually is unnecessary. For this reason the relay NUA may be energized through an alternative circuit which includes a switch TS7 closed during down peak periods and a cam-operated switch 68C which is closed only when the elevator car is at the lower terminal floor.

Next let it be assumed that the switch 67 in Fig. 4 is closed to permit assignment of the elevator car A under certain conditions to reverse at an intermediate landing. The conditions may be such that no down floor call or no car call is registered for a floor above such landing and that 110 up floor call is registered for such landing or for any higher landing while the elevator car is set for up travel and is approaching such landing.

For illustrative purposes, let it be assumed that the elevator car A is approaching the fourth floor and that a down floor call for the fourth floor constitutes the only call registered in the system. Under such circumstances, the down floor call registering relay 4BR is picked up and the break contacts 4DR2 (Fig. 4) are open by a sequence clear from the foregoing discussion.

As the elevator car nears the fourth floor, the brush 66 engages the contact segment k4 to complete the following circuit:

L+, 5DR2, SCX, 4UR2, k4, 66, 67, W7, J, L-

The relay .T closes its make contacts J1 (Fig. 2) to complete with the make contacts M1, an energizing circuit for the relays E, F and G. These operate in the manner previously described to stop the elevator car at the fourth floor. in addition, break contacts J2 open. As the elevator car stops at the fourth floor, the make contacts M7 of the running relay also open to deenergize the up-preference relay W. Since the up-preference relay closes its break contacts W2 to energize the down-preference relay X, the elevator car now is assigned for down travel.

Finally, the reversal relay 3' opens its break contacts J3 to prevent energization therethrough of the timing relay 701-11. The floor call stopping relay resets and opens its make contacts K2 slightly before contacts 13 reclose. Consequently, the relay 'I'tll-lT is ineffective for controlling the non-interference time.

The non-interference time of the elevator car now is controlled solely by the timing relays 701 and SRT. Consequently, the elevator car remains at the fourth floor for a maximum of five seconds. However, if a passenger leaves the elevator car or enters the elevator car within the five second period the non-interference time is reset to have a value of only one-half second. This t am-w operation of'the relays 70T andzSRTwillbeunderstood:

from thetforegoingdiscussion.

It the additional time provided-by thetimingrelay.

70HT; is desired for all floor calls the contacts J3 may be shunted by amanual switch 69A. The contacts M4 may then be given a slight time delay in closing. Under these circumstances the brush 58 is positioned to engage the' con-tact segment f4 when the elevator carstops at the fourth floor. Closure of the contacts X when the elevator car is set for down travel'energizesthe relay K andz'therelay K is then deenergized by reset of the registeringrelay 4DR following closure of the contacts M4. The momentary closing of the contacts K2 operates in the manner previously described to provide a minimum noninterference time of twoseconds; However, it will be assumed; that the switch 69A is openand that a reversal of the car at an intermediate floorprovides a minimum non-interference time of one-half second.

Asthe elevator car A on its. up trip approaches the upper terminal or fifth floor, the brush 23 (Fig. 2) engages the contact segment a5'to complete the following energizingcircuit for the car-call stoppingrelay:

" L+, a5, 23, W3, TT, M3, L

The .car-call stopping relay operates inthe manner pre viously discussed to stop the elevator car accuratelyaf the upper-terminal floor.

As the elevator car A reaches the upper-terminal floor, the mechanicalswitch 63' (Fig. 4) opens. Consequently, the elevator car A cannot start from the upper-terminal fiooruntil it is started by-its upper-terminal dispatching device represented by the contacts TTSl. It will be understood that the upper-terminal. dispatching: device maybe similar to the dispatching device discussed for the first floor. For present purposes-it will be assumed that the contacts TTSI operate for the upper-terminal dispatching floor in the same mannerby which. the contacts S1 operate for the lower dispatching floor.

As the elevator car reaches the fifth floor, the limit switch361(Fig. 2) opens to deenergize the up-preference relay W. This relay opens its make contacts W1, W3, W5, W6, Without immediately affecting the operation of the system. However, opening of the make contacts W4 deenergizes the holding coils for :the'car-call push buttons, and these are reset. In addition, closing of the break contacts. W2 completes the following energizing circuit for the down-preference relay:

L+, U6, W2, X, 37, 38, L-

The down-preference relay X closes its make contacts X1, X3, X4, X5 and X6 and opens=its break 'contacts X2-to condition the elevator car-fordown travel.

It will be assumed next that thedispatching device. for

theupper-terminal floor closes itscontacts TTS1'(Fig."

4 )and that the timing relay has closed its break contacts 70T2 to complete an energizing circuit for the starting rel-ay- 80.- The loading relay of the dispatching-device for the upper-terminal floor operates the contactsTNl tocontrol the door-control relay 45 in the same manner by which-contacts N1 control the door-control'relay at thelower terminal floor. The closing of thedoors coupled with the closing of the make contacts 80-'1 completes the following circuit for the down switch D and the=car-running relay- M:

L+., 80-1, X1, F2, 35, D, M, 40-1,L,-

and-.opensjts break contacts V2; V3; The: elevator-.car; now is conditionedifor movement inathedown direction at:

full speed and moves away fromthe upper terminal floor-t Closure. of make contacts DS establishes aholding.

circuit around the contacts -1 and X1. Opening (If! break contacts D6 has no immediate effect on theoperation of the system.

It willr be understood that as theelevator car leaflves -tl e upper terminal floor, the limit switch34 (Fig 2,) and the;

switch 63 (Fig. 4) reclose.,

it will be assumed next that a passenger in the elevator car operates the car-calli push button,3c for the purpose of'rcgistering -a car call forthe; third-floor. button connects the contact segments a3 and1h3.to=the-:

bus'L+. Also contacts 3cx opent When the brush 40'areaches, the contactsegmentihifi an energizing circuit is established fOIPtthfi-gCilIfyCfilLSfQliping relay TT as follows:

The speed relay opens its-make contacts-V1 to'introduceg the resistor R1 in series with the generatorfield Winding; 29C. The elevator car now slows to a landing speed. In addition, the breakcon-tactsv V2' close to complete an energizing circuit for the stopping inductor relay: Closure of breakccontacts V3 has noetfect.

When the stopping inductor relay F reaches the in;.,

ductor plate DFP for the third fioor, the. contacts F2 ,opet t to deenergizethe down switch D'andcthe car-running relay M. The down switch D opens its make contacts D1. to permit reapplication of the brake 17. Make contacts D2 and D3 open to deenergize the generator field winding, and the elevator car A stops accurately atthe third floor. Opening of the make contacts D4 and D5: and closing of the break contacts D6 have no immediate efiect on the operation of the system. As the elevator car comes to a stop the brush 40a may pass the contact segment h3 slightly to deenergize the relay TT.

The car-running relay M opens its make contacts Ml to deenergize the inductor relays and the holding relay G. The holding relay G in turn opens its make contacts. G1; to prevent subsequent energization therethrough of the inductor relays.

The make contacts M2 open to initiate an opening operation of the doors. The opening and closing of the; doors will be understood from theprevious discussion, thereof.

The car-running relay M also opens its make contacts M5 to start a timing-out operation of the timing relays 70T. Opening of make contacts M3 and M5 and closing of break contacts M4 have no immediate effect on the operation'of the. system. Break, contacts M6 close to, illuminate the lamps LA1 and L'AZ; When the timing relay 70T drops out, the; break contacts 70T2' (Fig:- 4) close to energize, through the switch 63 the startingrelay 80. The starting relay operates in the manner previously described to start the elevator cardown fromthethird floor. It will be recalled that the drop out of the relay 70T may be expedited by entry or departure of, a pass'enger relative to the car before the time delay of the relay expires.

Let it be .assumed'that instead of a car call adown floor callwas registered for the third floor by operationof the push button 3D (Fig. 3). Such operation energizes the down floor-call storing relay 3DR which closes its make contact 3DR1 to establish a holding circuit around. the'push button-3D.- Thecontact segment f3 andcorre- 

